Recovering gasoline



' LSWA-S F. E. HOSMER Filed May 4,

RECOVERING GASOLINE Nml.

Sept., 30 y 19241.

renna carica,

FRED E. BOSNIE', 0F SHBEVEPORT, LOUISIANA.

BECOVERING GASOLINE.

Application med May 4,

To all whom t may concern:

vBe it known that I, FRED E. HosMEB, a citizen of the United States,residing at Shreveport, in the parish of Caddo and State of Louisiana,have invented certain new and useful Improvements in RecoveringGasoline, of which the following is a specification.

This invention relates to recovering gasoline; and it comprises aprocess of recovering volatile oils from natural gas, refinery gas,etc., wherein such gas is submitted to compression and cooling torecover'a condensate and is thereafter scrubbed with,

higher boiling constituents oi such condensate to recover a furtherquantity of gasoline; and it also comprises apparatus convenient in theperformance of such process; all as more fully hereinafter set forth andas claimed.

As is -well known, large amounts of gasoline (casing head) are recoveredfrom natural gas in various ways. This gasoline is composed of manydierent hydro-carbon oils of varying volatilities; its particularcharacter in each. case `depending upon the particular gas undertreatment and the particular method adopted in recovery. Sometimesrecovery is by pressure and cooling;

sometimes by intense cold, and very frequently by the use of both. Inanother way of recovering gasoline, wash oils are used; the gas beinscrubbed with a heavy petroleum oil w ich absorbs the gasoline.Afterwards the charged oil is heated to distil ofthe gasoline and fitthe oil forreuse. All these methods have their practical inconveniences.High pressure and high refrigeration require an lextensive plant and thesame is true of the absorption method using heavy oil. In addition, theabsorption methods re' uire-a distilling plant and consum tion oconsiderable fuel.

T e gasoline produced by any of these methods, is, as stated, a mixtureof many oils of differing volatility; and for commercial purposes itcommonly needs further treatment. Quite commonly it is wild; that is, itcontains enough gases and very volatile oils to boil at ordinary airtemperatures; and in this event, it must be weathered to removel greateror less amounts of very volatile bodies. Where it is made by theabsorption process, it often contains some of the oil used in absorption1922. Serial No. 558,329.

or of its products of decomposition; it being diicult to heat any ofthese oils without more or less breaking down even at the low\distillati'on temperatures usually employed.

It 1s the object of the present invention to provide a method ofandmeans for recovering gasoline from natural gas, this method alsobeing applicable to refinery gases and other ases carrying vapors ofvolatile bodies.. n this method, pressure, cooling and absorption areall used, but the product itself is relied upon to furnish the absorbingoil.

In compressing and cooling a wet natural gas, even at moderate pressuresand not very low temperatures, there is always a separation of liquid.Further compression and further cooling will give morel condensation;but there is always some separation with moderate pressure and cooling,as stated. This condensate may be regarded as composed partly of theless Volatile oils Whose vapors occur in the gas and of the morevolatile oils taken up therein'by absorption or solution. For the sakeof nomenclature, these two portions may be respectively designated asthe low volatile oils and high volatile oils. Actually, of course, bothportions or fractions are usually highly volatile; but one is morevolatile than the other, and these terms are convenient. With such acondensatiom'of course, much or most of the high volatile oils escapeliquefaction and pass forward with the gas.

In the present invention, I submit the gas to a moderate pressure, andcool, thereby causing a condensation. Almost any convenientlow degree ofpressure may be used, say, from 5 to 50 pounds. High pressure may, ofcourse, be used, and in certain cases is advantageous but generally I donot use more than a moderate compression. This condensate Will be of lowvolatile oil saturated with high volatile oil. I remove it and releasethe pressure or expose it to suc- 100 tion. I may heat it more or lesst'o compensate for the absorption of heat in evaporation, but ordinarilythis is not desirable. Self-evaporation separates it into vapors of highvolatile oil which are elsewhere con- 105 rated from the firstcondensation, thereby 110 absorbing the residual uncondensed va rs ofhigh volatile .oils or most of them. he charged low volatile oil comingfrom the scrubbing apparatus. is agaln exposed .to self-evaporation, thevapors of high volatile oils being once more sent to condensation and tostorage, while the residual low volatile oils, or some of them, can bereused for absorption. Operating in this manner, it will be observedthat I utilize low pressure, moderate cooling and absorptiom'using forabsorption, however, nothing forel n to the gasoline to be produced; andthat directly produce two different products from my process: one beinglow volatile oils needing no weathering and the other, high volatileoils which can be used for any purpose desired. The two products can beblended with each other, or with other oils, in any proportions desiredto give 1products of any desired specific gravity or aum.

In the accompanying d` .wing I have shown, more or lessdiagrammatically, apparatus within the described invention and capableof use in performing the described process. The View is aconventionalized and diagrammatic showing in elevatiompartly in section.

In the showing, gas from a suitable source (not shown) enters the systemby pipe 1 on the suction side of pump or compressor 2 which is operatingunder any pressure desired. Ordinarily, rather low pressures are. used,say, 5 to 50 pounds,- valthough of course higher may be employed. Graslleaves the pump through pipe 3 and is cooled in diagrammatically showncooler coils 4. Cooled compressed gas passes by pipe 5 provided withvalved continuations 6 and 7 to accumulating tank 8, wherein separationof condensate from the gas takes place. Liquid passes \by pipe 9 pasttrap 10 communicating with valved line 11. As shown,

this line 11 enters a stripping tank 12 and supplies a diagrammaticallyshown spraying device 13. The condensate in the accumulating tank isthat previously described as a composition of low volatile oils and highvolatile oils. In the stripping tank high volatile oils are Vaporizedand the low volatile oils in a cool condition accumulate at the base ofthe stripping tank. The cooling action in the stripping tank may beutilized in giving further cooling to the compressed gas entering thesystem. For this purpose, a cooling coil 14 is provided in thestrippingV tank. Valved by-pass 15 allows the compressed gas to be sentthrough this coil. By this arrangement, the heat abstracted from the gasin 14 is utilized in the stripping action in tank 12. -The cooled gasfrom 14 may be returned by valved line 16 to the line (7) going to theaccumulator tank. The stripped low volatile oils from the stripping tankare removed through valved line 17 with theV aid of pump 18. The oils,or some portion of them, may go via pipes 19 and 20 to a stock tank 21.A portion of the stripped oil is taken by pipe 22 and used for scrubbingthe gas coming from the accumulator tank and still containing vapors ofhigh volatile oils. For this urpose, the diagrammatically shown scrubing tower 23 is provided. As shown, the scrubbing oils enter throughspraying device 24. The gas to be scrubbed coming from the accumulatingtank (8) by pipe 25 passes upward through the scrubbed in countercurrent to the descending oil. Scrubbed gas leaves the system throughpipe 26 provided with reducing valve 27. Low volatile oil used inscrubbing, which is now charged with high volatile nils', leaves thescrubber through pipe 28 and, passimjr trap 29, ma be sent to thestripping device through pipe 30 having sprayin means 31 within thestripping tank (12 The vaporized high volatile oils from the strippingtank pass via pipe 32 to 2-stage compressor 33. This compressormaintains suction in the stripping tank 12. The compressed vapors passthrough cooler 34 and return to compressor 33. They are there furthercompressed and are again cooled in cooler 35. The condensate formedpasses through line 36 to stock tank 37. Any uncondensed gases are ledto a place ofI disposition (not shown) by pipe 38 provided with reducingvalve 39. Condensed high volatile oils may be removed from this stocktank and sent to va place of disposition (not shown) by valved pipe 37a.Or the high volatile oils may be removed through pipe 40 with' the aidof pump 41 and, passing trap 42,

may be sent by line 43v to the first stock tank (21) mentioned forvreadrnixture, in such proportion as may be desired, with the lowvolatile oils therein accumulating. A by-pass' line is provided wherebyoils condensed in the first stage of compression and cooling in the2-stage compressor 33 may also'be sent to this stock tank (21). Theseoils condensed in the first stage of the compression are richer in lowvolatile oils than those formed in the second stage of compression. Thisby-pass line comprises valved line 44 communicating with the firstcooling coil (34), a trap 45 and pipe 46, shown as communicating withpipe 43. Special connections are provided whereby condensate from theaccumulator tank (8) may be'sent directly to the stock tank (21) withoutstripping. For this purpose, valved pipe 47 is provided communicatingwith line 11 beyond trap Mixed high volatile oils and low volatile oilswithdrawn by this line 47 ma pass, via pipes 48 and 43, to stock tank(21). In a similar way, charged oil from morenas the scrubber may bediverted by valved cross connection at t9 and sent to the stock tank 2l,via pipes 4:8 and t3.

F or simplicity of illustration, ll have shown but tWo stock tanks 37and 2l, but it will of course be understood that as man more may beemployed as may be desire As described, stock tank 37 serves primarilyfor the collection of high volatile oils and tank 21 of lovv volatileoils or of a mixture of lovv volatile oils and high volatile oils. Thetvvo tanks 37 and 21 may be reserved respectively forhigh volatile andlovv volatile oils and as many more tanks provided for blended productsas may be desired.

ln the use of the described apparatus and in the performance of thepresent process, it is not necessary to use any high degrec of pressure,although such hi h pressure may be employed; good resuts may be attainedwithout more pressure than is required to produce forward movement offthe gas under treatment. iimple cooling and vabsorption may be reliedupon. llt is, however, usually convenient to employ some pressure; andof course to the extent that it is used, cooling and absorption are mademore eiiicient. The line or Well pressure on the gas may be sutlicientto enable operation of the described apparatus.

1. lin the recovery of gasoline :trom gas the process which comprisescompressing and coolingthe gas, separating the condensate formed fromthe residual as, evaporating high volatile oils from t e condensate toform a residue of lovv volatile oils and scrubbin the residual gas withthe said low volatile oils.

2. In 'the recovery of gasoline fromgas, the process which comprisescoolin `such as, separatin the condensate t ereby ormed from e residualgas, evaporating the high volatile oils from such condensate andscrubbing the residual gas With the residual low volatile oil.

3. lin the recovery ot gasoline from; gas,

from such condensate, scrubbing the residual gas with the residual lowvolatile oil and recondensing the vapors of the high volatile oilsformed in said evaporation.

5. ln the recoveryof gasoline from gas, the process which comprisescooling such gas, separating the condensate therebyl formed from theresidual gas, evaporating the high volatile oils from such condensate,

scrubbing the residual gas with the residual lovv volatile oil toabstract high volatile oil t therefrom, evaporatin the high volatileoils absorbed by the scrulgoing and condensing the vapors ot highvolatile oils produced in said evaporating operations..

6. Apparatus for theireoovery ot gasoline from gas, comprising means forcondensing a portionof the oils contained in the gas, means forseparating the condensate from the residual gas, means Jfor evaporatingportion of the condensate and means for fi scrubbing the residual gaswith the residual oil. f

ln testimony whereof, ll have hereunto aixed my signature.

FRED E. HSt/ER.

